LIBRARY OF CONGRESS. 



Chap. Copyright No. 

Shelf___TAi1 vJ 

*-un 

UNITED STATES OF AMERICA. 






THE • • • tsiM-jt- 



CYCLOTOMIC TRANSIT 



DESCRIPTION OF A NOVEL SURVEYING 

INSTRUMENT 



. Made By 
./ 



THE A. LIETZ' COMPANY 

422 SACRAMENTO ST. 

SAN FRANCISCO, . CALIFORNIA. 

Copyright 1896, The A. Lietz Company, Son Francisco 



Will fc>e mailed to any address, on reeeipt of 

SO CEJNTS 



OUR REVISED EDITION 



OF THE 



MANUAL » MODERN SURVEYING INSTRUMENTS 



AND THEIR USES 



(200 Pages) 



Containing Useful Information and Tables for the 
Civil Engineers and Surveyors 



TOGETHER WITH A 



CATALOGUE AND PRICE LIST OF SCIENTIFIC INSTRUMENTS 



Particularly those of the Civil Engineer and Surveyor 



MADE BY THE 



A. LIETZ COMPANY 



422 SACRAMENTO STREET 



San Francisco, 



California 



THE CYCLOTOMIC TRANSIT 



Otto von Gkldern 

THE PRINCIPLE OF THE INSTRUMENT. 

The evolutiun of this instrument is due to a constant tendency to create a transit with 
one spindle, i. e., having but one central cone turning within the leveling head, that shall, 
at the same time, sacrifice none of the. advantages that the so-called compound center pos- 
sesses. 

It goes without saying that the principal advantage of the double spindle lies in the 
fact that, no matter in what direction the telescope maybe pointed, the operator is enabled 
to make any azimuth of his graduated plate agree therewith. How this may be done with- 
out giving the lower plate an independent motion around the vertical axis of the instru- 
ment, is the problem to be solved. 

The lower plate is the important member that carries the graduated azimuth circle, 
and if it be made a part of the rigid sub-structure — of the leveling-head and base-plate — 
the control of it in reference to known azimuths is apparently lost. If we were enabled, 
however, to shift the figure-series — the nomenclature of the circle — at will, so as to make 
any one of the graduation lines the zero, the advantage lost by having a rigid lower plate 
would be regained. 

The novelty of the new transit lies in a floating exterior ring, placed around the periph- 
ery of the lower plate, upon which the figures from o to 360 are engraved. These fig- 
ures are then no longer a fixed part of the circle, but possess that independent rotation 
which the lower plate had in the case of the double spindle. Instead of turning the whole 
plate around its vertical axis, we turn a narrow metal band around the stationary plate, 
which is the same thing. 

As this band appears to be sliced from the plate, the name Cyclotome has been applied 
to it, from kvkXoS, ring or circle, and rs/ureiv, to cut, that is, a ring cut or severed as 
from a disk. 

Since the object of the ring is merely to designate the graduated lines upon the plate 
by corresponding figures, absolute concentricity of the cyclotome is not a matter of import- 
ance. 

THE CONSTRUCTION. 

Attention is drawn to the illustrations herewith, figure I showing a vertical section 
through the plates, and figures 2 and 3 a top and bottom view respectively of the upper 
plate. In the vertical section the arrangement of the principal parts may be readily un- 
derstood. 

The lower plate and the leveling-head become one member, which is mounted upon 
the base-plate in the ordinary manner. The cyclotome C is fitted exteriorly around the 
plate, its top resting upon the graduation, of which it is a part. 

The upper plate revolves upon the lower by means of its long and stout spindle, within 
the socket of the leveling-head. It carries the vernier V t visible through an opening in the 
plate, which also exposes a part of the graduated lower plate and a part of the cyclotome. 




X- 




Fig. i. 



U O.-yr.O 



^Section through JPlate$ 

or? Or?e X - Center - Y, 
with sS/c/e v/ew ot** 7e/e<scope 



Patented March, 1896 



All rights reserved 




tfi*"9 



Fig. 2. 

Top We* °r "PP er P/afe 




Patented March, 1896 



All right* reservec 



The horizontal motion of the instrument is arrested by the clamp and collar, and the posi- 
tion adjusted by a tangent screw, as common to all transits. 

Compass box and telescope are mounted on the top of the plate, as usual. 
The flange forming the top of the lower plate is graduated into 720 even spaces of 
half-degree divisions. The vernier moves along the inner rim of this graduation, and is 
held whenever the line of collimation (the telescope) has the desired direction. In order 
to effect a coincidence between the vernier's zero and the nearest half-degree division line 
the entire vernier may be shifted independently to the right or left by means of the screw 
A, shown in the illustrations, and in the manner presently to be explained. 

And having thusly determined upon and indicated one of the 720 lines to be the initial 
or starter, it would be necessary only to bring the zero of the cyclotome— or any other read- 
ing for that matter— to match this line. 

In the simpler form of the new transit, the exterior ring or cyclotome is revoluble by 
hand around the periphery of the plate, and the required azimuth is thus readily set off In 
the improved form, as shown by the illustrations, the ring is encased, and so arranged that 
the upper plate in its rotation may or may not carry the cyclotome with it. It is picked up 
and revolved together with the telescope, or left at rest upon the lower plate in any desired 
position. It is wuhin the power of the operator to manipulate this at will, and there are 
two means of doing so, as will be noted further on. 

As it is generally required to place the zero upon the azimuth from which observations 
are started, an automatic catch L (see figure 3), having a small projecting pin n, is so ar- 
ranged that whenever it is desired to make the cyclotome travel together with the upper 
plate, the prn n must be made to drop into a hole provided for it in the cyclotome • the 
moment this takes place, the two (plate and cyclotome) are connected, and-this is a pecu- 
liar feature of the device-in such a position that the zero of the vernier V, and the zero of 
the cyclotome Care brought together, separated, of course, by the intervening graduated 
flange of the lower plate. If the vernier be now revolved with the upper plate, the figure- 
system will travel with it, their respective zeros coinciding. 

The bottom of the upper plate, figure 3, illustrates the mechanism with which all this 
is accomplished. Uis a guide, fastened to the plate, for the arc W, carrying the vernier V 
A strong spring S presses the arc against the slide T, the position of the whole being regu- 
lated by the exterior screw A, which allows the adjustment of the vernier already referred 
to. The catch L is poised in T. The screw B raises or lowers the catch, so that with it 
we may throw the cyclotome either in or out. A small spring under the catch L admits of 
this. 1 he mechanism is so simple that it needs no further description. 

With this device there is no difficulty in placing the zero of the horizontal circle so as 
to correspond with any pointing of the telescope. 

USE IN THE FIELD. 

The field manipulation is reduced to a minimum. 

Having set the instrument over a point (1) in the usual manner, it is desired to direct 
the telescope to another point (2), and to make the zero of the horizontal graduation corres- 
pond with this azimuth. The main clamp being loose, the first operation is to turn the 
screw i? so that the catch L is depressed ; the upper plate is then turned, until a click indi- 
cates that the little pin n has caught the cyclotome and is carrying it along, with the zero in 
position as explained. The operation is automatic to this extent, that the manipulator 
need not watch his plate to set the zeros. He will now direct the telescope to point (2), 
clamp the plate, and bisect the object with the tangent screw. His attention is thereupon 
directed to the vernier, for it is essential that its zero should corresoond exactly with a line 
of the fixed graduation. He turns the screw A to the right, or left, shifting the vernier 



sufficiently to accomplish this. The cyclotome travels with the vernier, so that he does 
not need to watch it. The instrument is now oriented, the vernier indicating the starting 
azimuth, -and measurements to other points may begin. Before commencing, however, the 
screw B is turned so as to release the catch and allow the cyclotome to remain in position. 
The instrument is now undamped and ready for operation. Any subsequent reading will 
indicate directly in degrees and minutes the deflection from the starting point. The whole 
operation is simple and rapid, and will require less time than the setting of the compound - 

center instrument. 

If it be desired to set any other azimuth to a telescope pointing, recourse is had to the 
clamp F (see top view of plate, figure 2), by which the cyclotome may be connected to the 
upper plate at any point. 

The operation it as follows : 

Set up instrument ; drop catch L by a turn of screw B ; revolve plate on center, click 
indicates that L has caught cyclotome C; point telescope, clamp plate and bisect object ; 
shift zeros to the nearest graduation line by screw A ; release cyclotome by screw B ; un- 
clamp instrument and lay off the reading of the required azimuth to the nearest thirty 
minutes by means of the clamp and tangent screws, and then to the minute with precision 
by means of the screw A ; now turn down the screw F, which catches the cyclotome ; un- 
clamp instrument, revolve on center, direct telescope to original object, clamp and bisect. 
The reading of the vernier will now indicate the azimuth wanted. Release the screw F 
and the cyclotome will remain in the position into which it has been brought. 

The reason why the reading is laid off to the nearest thirty-minute mark only, and then 
adjusted to precise reading by shifting the vernier, becomes obvious, if we remember that it 
is always necessary to match the graduation lines of the plate with those of the cyclotome, 
and that any setting disturbing their coincidence (readings from V to 2Q X and 31* to 59') will 
have to be corrected by a vernier displacement. 

This operation is rapid, although perhaps a trifle slower than the manipulation with 
the hand cyclotome, mentioned above, in which case the telescope is directed, plate clamped, 
object bisected, vernier zero brought to a line, cyclotome turned by hand to read within the 
nearest half degree of the line, after which the vernier is adjusted to the exact reading. 

The principle remains the same in either method, the only difference being that in the 
case of the hand cyclotome one is able to set it irrespective of the motions of the uppe 

plate. 

After these explanations it becomes very obvious that there are no advantages that the 
double spindle system can claim over the cyclotomic system in the ready manipulation of 

the horizontal arc. 

ANGULAR REPETITION. 

While the reiteration of an angle, resorted to in geodetic measurements, to obtain the 
value of an arc with its probable error to the fraction of a second, is not possible with the 
cyclotomic transit, because the main graduation is fixed and cannot be turned in reference 
to the direction of -the objects observed upon, it is perfectly feasible to take the same angle 
on different parts of the plate. Since there are two verniers, located 180 degrees apart, two 
readings may also be had of each measurement and the mean taken. 

Unless a double spindle transit be of the very best workmanship, that is, a first-class 
and therefore a high-priced article, all the reiteration and repetition will fail to reach a 
better result than that attainable with a well built cyclotomic instrument, which is made to 
read to half minutes directly, or to twenty seconds in the larger sizes ; and anything within 
the limits of this accuracy is guaranteed by the maker. As the reiteration of an angle is 
uncalled for in any but the most refined measurements, the cyclotomic transit does not lack 
completeness for the want of this particular feature. 



ADVANTAGES OF THE CYCLOTOMIC TRANSIT. 

The main feature is its single spindle. Its adoption obviates the necessity of the lower 
clamp and tangent screws, and simplifies this part of the transit very much. It affords an 
opportunity to br.ng the plates closer to the leveling-fiead, thereby lowering the center of 
gravtty of he mstrument. It sits directly upon the rigid substructure, fitted into " by a 
thuk metal ax.s and must therefore be very steady. The main gradual on the mo vftal 
part of the trans.., is fixed for all time. Once properly centeredfthe chance for eccenH 
ty are reduced to a minimum. The instrument possesses a comp ring vernier oppos te he 
readmg venue,, (see figure 2) which shows through a circular opening i„ , e pfate Bv 
means of he two used in conjunction, the plate eccentricity may be accurate,^ de te mined 

cente^tit^t tt %£?* " - — s *" -UK 

and the least habdity to serious injury throueh accident . =; m „i c grater rigidity, 

more rapid setting of the plates to the zero Z,,i ^ I mechanlsm enabling a 

ard o(Vt«T l apP ,° intmen,s and constructive details, the instrument is up to the stand 

and £il^^11 b ^^^ "~" -th a cheap 
ble the stability and concentricity, without fos gXe 1e „r s Tha l^V P "f" 
the double-center instrument the preferred one for meelg the 11 f«M d 7 '" "^ 

the profession upon a universal measuring tool. 2 ^ ^^^ ^ ^ 

THE MANUFACTURE. 

The instrument in its present shape was designed in detail by Mr Adolnh T i,t ,K 
ongmal suggestion having been made to him by Mr Luther W»L , P ' 

San Francisco who had conceived the applicaJn of'.htt «£ ^ %£T" " 

AU n gh s have been lega|)y secured by the whQ S 8 r »me- 

The ins rument is made in San Francisco, in different styles and sizes "„,hT • 
and esseneal parts all styles are alike, but they may vary a Met T' "^ 

rn.no, detail. In appearance the instrument does not diffjfrom a n I d "T*™* °' 
that the bulky apparatus of clamp, collar toneue snrinH T* ' yp£ * eXCept 

Piates is missing, and that the pLs ta hTcioser 7ZIZ ^ ^ **" "» 

Ine cyclotomic transit is particularly adan^rl fo oi •• 
light superstructure upon a fi™ and so in base TMs «~ ^^^ ^ P'~ in g a 
in a strong wind. ' ,nsure ver ? g reat steadiness even 



REMARKS. 



It is very probable that the instrument will work itself into the favor „f ,h, V ■ 
ll^Lt^ ™ h *'« — g - been sacrificed^tneltem 7^2 

rule, wil, brapp ia ted a t„: ^,1" f "* *' ^ ^ l0t ° me ' whi ' h > «*• 'h, slide- 

yt> ^uiaucu an rne more the longer it is used anrl ,,o „j . , 

apparent. & anct lts advantages become 



ILLUSTRATED PRICE LIST 



OF THE 



Cyclotomic Transits 



(PATENTED MARCH, 1890.) 



GUARANTEED EIRST-CLASS IN EVERY DETAIL 



MADE BY 



THE A. LIETZ COMPANY 



MAN UFA CT UE EBS OF 



Scientific Instruments 



422 Sacramento Street 

SAN FRANCISCO 

C.A.X.- 



THE CYCLOTOMIC TRANSIT. 
(Patented March, 1896.) 



fHE instrument is first-class in every particular, and made to correspond in 
all details to our high-grade transits; it is intended for any of the most 
accurate work the engineer is called upon to do. 

It has but one spindle, but the simple arrangement of the 
Oyclotome admits of every evolution that the double center is 
capable of carrying out. 

Its invention is the result of a constant aim on our part to create a simple 
long center instrument, against which it may not be said that the value of a 
horizontal angle cannot be determined at once, without taking two readings 
and obtaining a calculated difference. 

The design is novel, but several instruments have been out in the field 
for months and are giving absolute and perfect satisfaction. 

The instrument contains the best optical accessories, the most accurate 
plate divisions, and is guaranteed to give results to the limits of its vernier 
graduations, which may be had to twenty seconds of arc, if desired. 

The high-grade Oyclotomic Transit is made in two sizes, of dimensions 
similar to our other transits, and these sizes are manufactured either in red 
metal or aluminium. They are numbered 18 for the larger and 18a for the 
smaller size. 

A complete Oyclotomic Reconnoissance Transit, No. 18b, is also 
manufactured, in which the advantages of the system are combined to make a 
reliable instrument, complete in every detail, for any work in the line of 
modern engineering, at the most reasonable cost. See page 12 for details. 

We recommend the Oyclotomic Instrument to the profession. Its use 
and manipulation are extremely simple, and the results of its work absolutely 
reliable. 

Any special information, if called for, will be furnished. 

After exhaustive trials we have the greatest confidence in the future of the 
cyclotomic method, and for this reason we have gone extensively into the 
manufacture of this novel design. 




No. 18. 

CYCLOTOMIC TRANSIT. 

Price, as shown complete, but without Gradienter, $200.(M). 

For details and extras, see the following page. 



10 

No. 18. 

COMPLETE CYCLOTOMIC TRANSIT. 

{Patented March, 1896.) 
Dimensions and Weight. 

Horizontal circle (measured to edge of graduation) 6^ inches diam. 

Vertical circle " " " 5 " " 

Compass needle 4% " long. 

Object glass 1% " diam. 

Telescope I i " long. 

Magnifying power 24 

Weight of instrument 15 lbs 

tripod 8% '• 

" box 8 

Weight of this instrument if made of hard aluminium 7% '' 

The price of this instrument complete, as shown is ... $200 00 

And if made of hard aluminium, 15 pei cent addedo 

No, 1 8a. 
COMPLETE CYCLOTOMIC TRANSIT. 

(The same as No 18, but smaller.) 

Dimensions and. Weight. 

Horizontal circle (measured to edge of graduation) 5 inches diam. 

Vertical arc or ci cle (measure d 10 edge of graduation) 4 " " 

Compass needle . 3 ^ " long. 

Object glass ... - 1 " diam 

Telescope 8 " long 

Magnifying power . . , 18 

Weight of instrument 8)4 lbs. 

" tripod 6 " 

box 6 

Weight of this instrument if made of hard aluminium. . . 4^ '* 

The price of this instrument complete is $195 °° 

And if made of hard aluminium, 15 per cent added. 

The Extras, for which additional charge is made for either size, except 
where noted, are as follows : 

Solid silver graduations : 

On horizontal cbcle $10 00 

On vertical arc or circle 5 00 

Verniers (horizontal) reading to 30" (No. 18) 10 00 

" " " " 20" (No. 18) 2000 

Gradienter attachment 5 00 

Stadia hairs, fixed 3 00 

" " adjustable 10 00 

Variation plate 10 00 

Arrangements for offsetting right angles 5 00 

Striding level to axis of telescope 20 00 

Reversion level (see slip 134A) 10 00 

Constructed with three leveling screws on base plate, instead of f< ur 10 00 

Three leveling-screw shifting center 5 00 

Prism, attachable to eye-piece 8 00 

Extra extension tripod 1 5 00 

Extra tripod, in lieu of the ordinary . 5 00 

Protection bag ■ I 00 

Bottle of fine watch oil 25 

Saegmiiller solar attachment of aluminium 50 00 



11 




No. 18 b. 

COMPLETE CYCLOTOMIC RECONNOISSANCE TRANSIT. 

Price, as shown complete, $125.00. 

For Extras and Details, see the following page. 



12 



No. 18b. 
COMPLETE CYCLOTOMIC RECONNOISSANCE 

TRANSIT. 

{Patented March, 1896.) 

A field instrument of medium size, possessing a very large; needle, 
one horizontal vernier, verticle arc or circle, and every accessory to make 
the instrument a complete tachy meter for stadia work. For topography it 
has no equal in simplicity of operating parts, and full equipment for work of 
such character. 

It admits of laying off horizontal and vertical angles correctly to one 
minute of arc; the starting azimuth may be made zero or any other reading, 
with as much facility as any other known transit, although the instrument has 
only one spindle. This spindle or center is of extra large dimensions in length 
and diameter, which affords great stiffness and rigidity to the whole structure. 

Dimensions and Weight. 

Horizontal circle (measured to edge of graduation) 4 inches diam. 

Vertical arc (or circle) 4 " 

Compass needle . A% " long. 

Object glass J4. " diam. 

Telescope 8 " long. 

Weight of instrument 7^ lbs. 

" tripod 6 

" box 5 

Weight of this instrument if made of hard aluminium. 4J4 

The price of this instrument, complete, is $125 00 

And if made of hard aluminium, 15 per cent, added. 

The Extras, for which additional charge is made, are as follows: 

Stadia hairs, fixed $ 3 00 

Variation plate 10 00 

Extension tripod in lieu of the ordinary 5 00 

Protection bag 1 00 

Bottle of fine watch oil ... . 25 






tK ARY 0F CONGRESS 




30 



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